Abstract: Provided are systems and methods for forming a casing liner in a wellbore of a hydrocarbon well. The forming including disposing a casing liner print head in an annular region located between a casing pipe disposed in a wellbore of a hydrocarbon well and a wall of the wellbore, conducting a downhole lining operation including operating the casing liner print head to eject casing liner integrated structure material into the annular region to form, in the annular region, a casing liner integrated structure including contiguous voids formed in the casing liner integrated structure material, and depositing a cementitious material into the contiguous voids formed in the casing liner material to form, in the annular region, a casing liner including the casing liner integrated structure material and the cementitious material.

Abstract: The invention relates to a method of conducting a perf wash cement (“P/W/C”) abandonment job in an offshore oil or gas well annulus (2), in particular the washing or cementing operation using a rotating head (6, 8) with nozzles (7, 9) dispensing wash fluid or cement at pressure. Certain values of parameters of a washing or cementing job have been found surprisingly to affect the quality of the job, or the degree to which they affect the quality of the job has been unexpected. These include including rotation rate of the tool, the direction of translational movement of the tool, and the volume flow rate and pressure per nozzle of cement or wash fluid (and hence nozzle size).

Abstract: Apparatuses and methods for positioning a flexible hose into a wellbore with a protective housing are disclosed. A flexible hose is contained within a protective housing and both are positioned into a wellbore to a desired depth. Pressure can be applied to an interior of the protective housing, and a packoff seals between the flexible hose and the protective housing, causing the pressure to eject the hose from the protective housing.

Abstract: A port assembly for controlling fluid flow through a flow port of a port sub. The port assembly comprises a dissolvable barrier, a burst disk for protecting the dissolvable barrier from fluids inside the port sub, and optionally a protective layer for protecting the dissolvable barrier from external fluids. When the burst disk is ruptured by increased fluid pressure inside the port sub, the dissolvable barrier starts disintegrating from exposure to the fluid. When the dissolvable barrier and protective layer are broken through, a flow passage is opened in the port assembly to permit fluid flow therethrough. The flow passage may be positioned tangentially in the port sub. The breakthrough time of the dissolvable barrier may be preconfigured by providing one or more thinner areas therein and/or placing a corrosive material in the port assembly.

Abstract: Techniques described herein relate to a well completion including an engineered production liner extending into a reservoir. The engineered production liner includes limited-entry liner (LEL) valves configured to open to allow an acid solution to jet into the reservoir during an acid stimulation process, and close to prevent production fluid from flowing through the LEL valves when the well completion is put into production. The engineered production liner also includes pre-packed chemically-infused material (CIM) cartridges including production chemicals, and openings that align with the pre-packed CIM cartridges. The openings are plugged during the acid stimulation process to force the acid solution to flow through the LEL valves. The pre-packed CIM cartridges and the openings are configured to allow the production fluid to absorb a portion of the production chemicals as it flows from the reservoir into the engineered production liner when the well completion is put into production.

Abstract: The invention relates to the field of drilling. A packed-hole assembly comprises a drill bit, and a positive displacement motor having a bending unit for deviation by a tilt angle f, and further comprises a rotation module and a hinge module which are rigidly connected to one another, to drill pipes and to the motor by threaded connections. The rotation module consists of a fixed shaft with a central channel and axial openings for drilling fluid, and a rotating body with radial channels which is mounted on cageless rolling contact bearings such as to be capable of circular movement as a result of the reactive force of drilling fluid flowing into the annulus of the borehole through the axial openings in the shaft, the space between the shaft and the rotating body, and the radial channels in turn.

Abstract: A vectored annular cleaning system (VACS) includes a tool body having a first end, a second end, an outer surface and an inner surface defining an internal bore. A valve system is arranged in the internal bore. The valve system includes a valve and an actuator member including a central passage. The actuator member extends from the valve toward the second end. A valve actuator is shiftably connected to the tool body and mechanically connected to the actuator member. The valve actuator includes a plurality of drag blocks and one or more spring members. The one or more spring members radially outwardly bias the plurality of drag blocks.

Abstract: A casing shoe having a composite body portion, a coupling portion attached to one end of the body portion, and a one-way check valve assembly positioned in the body portion, the valve assembly and body portion having a centerline nozzle and a plurality of circumferentially spaced smaller diameter nozzles positioned around the centerline nozzle.

Abstract: An earth stabilization system includes a plurality of hollow jars positioned within ground to be stabilized, the jar walls formed from a concrete material or mix. The jars include a base cutter including a plurality of teeth coupled to a jar wall at or near the wall bottom, the base cutter including at least one material other than concrete, e.g., metal, diamond tip or carbide tip. The jars can be coupled to a turning tool that can cause rotation of the jar to turn or drive the jar into the soil mass or waterbed. The turning tool effects rotation of the jar and the base cutter, and the weight of the jar and the base cutter at least in part enable the jar to penetrate the ground to be stabilized. Displaced soil or other earthen material can move through a bore in the wall of the jar while the jar is being screwed into the soil in the direction of the wall bottom to the wall top. The base cutter of each jar can be welded to reinforcing material in a jar wall.

Abstract: A pumping system and a method operative to utilize at least two downhole pump assemblies to produce hydrocarbons from at least two locations of a subterranean reservoir, wherein the pump assemblies are controllably adjusted to synergistically provide uniform draw down from the wellbore.

Abstract: A water-abrasive cutting system includes a cutting head (2) which includes a fixing device (16, 18, 20) for fixing the cutting head (2) on the wall to be cut as well as a nozzle head (10) disposed on the cutting head (2). At least one cutting nozzle (12), for an application of a cutting jet (14), is disposed in the cutting head (2). A cutting monitoring device (26) includes at least one hydrophone (30) and at least one further sensor. The cutting monitoring device (26) is configured to detect a complete penetration and/or cutting-through of the wall on the basis of the sensor signals of the hydrophone (30) and the at least one further sensor.

Abstract: A downhole tool includes an outer sub and a mandrel positioned within the outer sub. The outer sub and the mandrel are tubular. The interior of the mandrel defines a bore flow path, and the annular space between the outer sub and the mandrel defines an annular flow path. One or more nozzle ports are formed in the mandrel to fluidly couple the bore flow path and the annular flow path. A nozzle is positioned in each nozzle port. The nozzle includes a nozzle body having a flow path formed therein to fluidly couple the bore flow path to the annular flow path through the nozzle.

Abstract: An injection tip assembly 10 and methods for use more reliably provide for delivery of fluid substances, such as materials that promote removal, destruction, or isolation of contaminants, into targeted zones within soil or bedrock. The injection tip assembly permits the application of pressurized fluid 163 so as to erode or cut a desired cavity or eroded volume 164 within the subsurface 14, allows for timely observation, adjustment, and control of pressure within the cavity, and directs the delivery of a second substance or fluid that may incorporate desired materials. The consequence of managed erosion and pressure control is to nucleate and propagate a hydraulic fracture of desirable form that optimally delivers remedial agents throughout the targeted formation.

Abstract: An automatic downhole jetting system for advancing a string and automatically operating a valve mechanism upon contact with a restriction in a wellbore. A jetting unit receives a working fluid, and an activation unit slidably engaged with the jetting unit. The jetting unit includes the valve mechanism for controlling fluid flow out through angled jet ports or through the activation unit. The activation unit can move toward the jetting unit upon contact with a restriction in the wellbore. The activation unit activates the valve mechanism, thereby allowing fluid to flow past the activation unit to remove the restriction. Upon removal of the restriction, the fluid flow deactivates the valve mechanism, thereby closing fluid flow past the activation unit and continuing jetting operation.

Abstract: A completion apparatus for a wellbore includes several flow tools and an actuation mechanism. The flow tools have a piston defining first and second chambers with a housing. The chambers communicates with hydraulics so the piston are movable in response to the communicated hydraulics. A sleeve disposed in the housing is movable with the piston between first, second, and third positions. The sleeve can have a seat movable between two conditions for passing/engaging plugs. The sleeve in the first position closes off communication through the first and second ports, and the sleeve in the second position permits communication through the first port and closes off communication through the second port. The sleeve in the third position closes off communication through the first port and permits communication through the second port. The actuation mechanism is operable to communicate the hydraulics respectively with the chambers of the flow tools.

Abstract: A cross over tool includes, a first tubular forming part of a structure having a channel formed radially through a wall thereof and having a passageway formed longitudinally through the wall. The tool includes a second tubular forming part of a tool string, the second tubular is positionable radially of the first tubular, and has a port through a wall thereof, the port is alignable with the channel. The crossover tool is configured such that while the a port is aligned with the a channel fluid can flow through an inside of the tool string radially through the a port and the a channel and back into the inside of the tool string and through the a passageway and through an annular space defined between the tool string and the structure.

Abstract: A threaded connection body is welded to the wall of a pipe, seachest or other flooded cavity within the hull of a ship or floating offshore installation. A sealed cutting apparatus is mounted via a valve unit n the connection body and a cutter extended through the open valve to form an opening in the wall. After retracting the cutter and closing the valve, the cutting apparatus is replaced by an inspection unit having a camera which is extended through the valve and the opening to inspect the cavity. After retracting the camera and closing the valve, the inspection unit is replaced by a plug deployment unit which advances a plug through the valve and screws it into the connection body. The valve unit can then be removed and replaced with a cap so that the plug and the cap provide a double seal to the connection body.

Abstract: A system for use with a subterranean well can include a tubular string with a fluid discharge apparatus, the fluid discharge apparatus including a curved flow path which directs a fluid to flow less toward a structure external to the tubular string. A fluid discharge apparatus can include a generally tubular housing having a longitudinal axis, and at least one curved flow path which directs fluid to flow more parallel to the longitudinal axis from an interior of the housing to an exterior of the housing. A method of mitigating erosion of a structure external to a discharge port in a well can include directing a fluid to flow through a curved flow path, thereby reducing impingement of the fluid on the structure in the well.

Abstract: Provided is a water jet peening apparatus and a water jet peening method including: a clamping cylinder (201) which is able to be disposed at the outer peripheral side of an instrumentation nozzle (83) with a predetermined gap therebetween; a clamping piece (210) which is able to fix the clamping cylinder (201) to the instrumentation nozzle (83); a nozzle guide (221) which has a cylindrical shape, is provided inside the clamping cylinder (201), and is positioned to a position adjacent to the upper end of the instrumentation nozzle (83); an inner surface WJP nozzle (105) which is movable upward and downward inside the nozzle guide (221); and a drainage hole (224) which radially penetrates the nozzle guide (221). Accordingly, it is possible to improve the safety of the operation by preventing a thimble tube from being popped out due to a water jet peening operation.

Abstract: A flexible wellbore casing guide having a tubular body positioned at an end of a wellbore casing having a lower stiffness than the wellbore casing, the casing guide can be a section of fiber reinforced composite tubing.

Abstract: A smooth bore toe valve includes a first sub defining a through bore and a fluid flow path through a wall thereof; a second sub; a housing mechanically engaged with the first and second subs to define a valve cavity axially between the first and second subs and to define a chamber radially between the first and second subs and the housing, the housing further defining a plurality of openings in a wall thereof; and a sleeve disposed within the chamber between the housing and the first and second subs to close the openings and, upon application of fluid pressure horn the through bore through the fluid this path, open the openings to fluid flow from the valve cavity to the exterior of the housing. A method for using such a valve is also disclosed.

Abstract: A method includes conveying a casing cutting tool into the wellbore lined with at least one casing string and cement, and stroking the casing cutting tool over a predetermined axial length of the wellbore while ejecting fluid from one or more nozzles in the casing cutting tool and thereby forming a plurality of longitudinal cuts through the casing string and cement. The casing cutting tool is then rotated about its longitudinal axis at two or more axially offset locations along the predetermined axial length while ejecting fluid from nozzles and thereby forming a plurality of axially offset transverse cuts in the casing string and the cement. The longitudinal cuts and axially offset transverse cuts form wedges in the wellbore, and the wedges are dislodged from the wellbore to expose formation rock along the predetermined axial length.

Abstract: An assembly for cleanout of scale buildup from a wall of a hydrocarbon well. The assembly is configured to be deployed and operated under pressure without the requirement of coiled tubing to deliver cleanout fluid. The assembly may include a plug for sealing against the wall of the well immediately above the location of scale buildup. A cleanout tool, such as a jetting nozzle may be coupled to the downhole side of the plug. Thus, fluid and pressure may be provided to the well uphole of the plug. In this manner, the plug may direct the fluid to the jetting nozzle to achieve cleanout of the scale buildup.

Abstract: A system and methodology facilitates an operation utilizing coiled tubing. The technique comprises coupling a hydraulic assist device to coiled tubing. A fluid is flowed into an enclosure such as a wellbore and along the coiled tubing. The fluid is flowed against the hydraulic assist device, and the action of this fluid against the hydraulic assist device creates a pulling force on the coiled tubing. The pulling force facilitates movement of the coiled tubing along the wellbore or other enclosure to provide the coiled tubing with greater reach for a variety of intervention operations or other types of operations.

Abstract: A system for use with a subterranean well can include a fluid oscillator which discharges pulsating fluid from a tubular string in a direction at least partially toward an end of the tubular string proximate a surface of the earth. A method can include discharging a fluid from the tubular string, thereby applying a reaction force to the tubular string, which reaction force biases the tubular string at least partially into the well. Another method can include discharging a pulsating fluid from a fluid oscillator in a direction at least partially toward an end of the tubular string, and drilling into an earth formation with a drill bit connected at an opposite end of the tubular string in the well.

Abstract: A downhole tool to separate liquid from a drilling fluid includes a multi-vein cyclonic separator disposed within a housing, the cyclonic separator including at least two veins extending in a spiral along the length of the cyclonic separator, holes in the housing positioned adjacent to edges of veins of the cyclonic separator to allow liquid accelerated from the drilling fluid to exit the housing, and wherein the cyclonic separator is configured to provide high centrifugal forces to the drilling fluid downhole.

Abstract: Provided are an apparatus and method for solution mining using cycling process in which a solvent is injected into underground useful ores to dissolve the useful ores and then collected again to obtain the useful ores. The cycling solution mining method includes a boring process for excavating the underground up to an ore deposit, a fracturing process to generate cracks in the ore deposit, an injection process for inserting a mining apparatus including an insertion rod having a pipe shape up to a lower portion of the well to inject a solvent that dissolves the useful ores into the ore deposit through the insertion rod, wherein a rotation force is applied to the solvent discharged from the insertion rod to increase a diffusion force of the solvent, and a production process for collecting the solvent, in which the useful ores are dissolved, again.

Abstract: A well cleanout tool configured to replace a joint of tubing in a multi-joint tubing string for a wellbore. The well cleanout tool having a bushing threadable to a tubular and a one piece integral nozzle threaded to the tubular opposite the bushing, with an inner gas separator assembly contained within the tubular for flowing particulate out the nozzle end and cleaned wellbore fluid out the bushing end.

Abstract: A fracturing jet nozzle assembly features a series of angles nozzles on a rotatably mounted plate that operates in conjunction with a central nozzle or nozzles. The slanted nozzles are aimed into the perforation where the central nozzle is aimed directly so that the rotation of the nozzle plate from the slanted nozzles results in cyclic impacts in the perforation from where the fractures will propagate. The cyclic loading results in greater fracture formation and propagation. In another variation, relatively movable plates employing slanted nozzles rotate one plate with respect to another to get the effect of cyclic pulses of jetting fluid impingement in the perforation to enhance formation and propagation of fractures from the perforation.

Abstract: A method is for the combined perforation, cleaning, and the subsequent plugging of a longitudinal section of a well. The well is provided with two pipe bodies placed substantially concentrically. The method includes lowering a perforation tool into the innermost pipe body to the longitudinal section, forming perforations in both pipe bodies along the longitudinal section with the perforation tool, cleaning the longitudinal section with a flushing tool which is attached to a lower portion of a string allowing through-flow, pumping a fluidized plugging material down the string and into the innermost pipe body at the longitudinal section, and placing the fluidized plugging material in the innermost pipe body, and thereby also into the entire cross section of the well via the perforations within the longitudinal section. A flushing tool is for cleaning the longitudinal section of the well.

Abstract: A method and system are provided for injecting high pressure abrasive fluid into an abrasive jet tool. The method and system comprise a slurry tank connected to an abrasive hopper and a low pressure abrasive pump for circulating abrasive slurry and transferring the slurry to a high pressure vessel. The method and system also contain a high pressure non-abrasive pump connected to a high pressure valve for pressurizing the high pressure vessel prior to injecting abrasive fluid into the abrasive jet tool.

Abstract: An abrasive perforator tool with a bypass flow channel. The tool comprises a tubular body or housing with perforating nozzles in the sidewall. A sleeve assembly inside the central bore of the tool provides for sequential deployment of first and second sleeves. Prior to deployment of the sleeve assembly, pressurized fluid can be passed through the tool to operate other tools beneath the perforator in the bottom hole assembly. Deployment of the first sleeve diverts pressurized fluid through the nozzles for perforating. Deployment of the second sleeve redirects the pressurized flow through the outlet of the tool to resume operation of other tools below the perforator.

Abstract: An apparatus for securing and using hydrajetting tools within a borehole includes a housing that defines an inner bore. A flow limiting member may be disposed within the inner bore. The flow limiting member may include a first a first jet in fluid communication with the top of the housing, a first chamber positioned below and in fluid communication with the first jet, and a first cavity aligned with the first jet and in fluid communication with the chamber. A groove may be disposed on an outer surface of the housing, with an anchor assembly that is disposed around the housing and axially slidable and securable within the groove.

Abstract: A system monitors and controls the injection of additives into formation fluids recovered through a well may include a plurality of nozzles that receive the injection fluid from an umbilical disposed in a well. Each nozzle may have an associated flow control element that is configured to affect a flow of the injection fluid ejected through the associated nozzle. The umbilical may include one or more filters positioned in a first of two parallel conduits formed along the umbilical. An occlusion member restricts in a second of the two conduits. The occlusion member permits flow in the second conduit after a predetermined pressure differential exists in the second conduit. The system may include a plurality of pressure sensors disposed along the umbilical, and an injector unit that dispenses fluid into the umbilical. A controller operatively coupled to the injector unit operates the injector in response to measurements from the pressure sensors.

Abstract: A contoured boss for conforming to an outer surface of a tubular member for deployment within a subterranean formation, the contoured boss comprising a valve receiving body having a contoured outer surface that extends radially outward from an outer surface of the tubular member; and passage for receiving a valve, the passage extending through the valve receiving body. A method for facilitating stimulation treatments in completions and a method of centering a tubular member having an outer surface within a borehole are also provided.

Abstract: A method of controlling a fluid jet can include discharging fluid through an outlet of a jetting device, thereby causing the fluid jet to be flowed in multiple non-coplanar directions, and the fluid jet being directed in the non-coplanar directions by a fluidic circuit of the jetting device. A jetting device can include a body having at least one outlet, and a fluidic circuit which directs a fluid jet to flow from the outlet in multiple non-coplanar directions without rotation of the outlet. A method of drilling a wellbore can include flowing fluid through a fluidic switch of a jetting device, thereby causing a fluid jet to be discharged in multiple non-coplanar directions from the jetting device, and the fluid jet cutting into an earth formation.

Abstract: A system, apparatus and method for abrasive jet fluid cutting is provided wherein an abrasive jet fluid cutting assembly comprises a hose for receiving a coherent abrasive jet-fluid containing a solid abrasive; a helix/spring attached inside the high-pressure hose; and a jet-nozzle connected to the hose. Wherein the coherent abrasive laden jet-fluid is pumped under high pressure through the high-pressure hose and across the helix. As the jet-fluid traverses the helix, the jet-fluid rotates at a high rate creating a vortex. The disclosed subject matter further includes a system and method for using the abrasive jet fluid cutting nozzle assembly.

Abstract: An apparatus for controlling a flow of a fluid between a wellbore tubular and a formation may include a frac tool having at least one port in selective fluid communication with the formation, and an inflow control device having a flow control path configured to provide a predetermined pressure drop for a flowing fluid. The inflow control device may have a flow coupler configured to provide selective fluid communication with the at least one port.

Abstract: Disclosed is a nozzle apparatus attached to a pressurized liquid source wherein the nozzle apparatus that can be inserted downhole into a well casing. The nozzle apparatus comprises an attachment component of at an open end of a hollow cylinder that comprises the nozzle. The nozzle is in communication with a pressurized liquid supply source. The hollow cylinder extends from the attachment component. The cylinder has a closed end; and a plurality of apertures extending from an interior surface of the hollow cylinder to an outer surface of the hollow cylinder sides. The outer surface of the nozzle cylinder can be uneven. The outer surface of the nozzle cylinder can have an unequal radius. The nozzle surface can contain bypass slits. In one embodiment the nozzle can have a threaded attachment component at the bottom. A scrapper or other cleaning device can be attached to the threaded component.

Abstract: A tubing conveyed tool for use in perforating a well bore utilizing abrasive perforating techniques. The perforating tool is particularly useful in non-vertical wells. The perforating tool is designed to permit running and setting a bridge plug, and then perforating the well bore without requiring the removal of the tool string. An eccentric weight bar can also be used to allow for directional perforating in non-vertical wells. The eccentric weight bar uses gravity to cause the bar to rotate to a predetermined position.

Abstract: A jetting tool includes a tubular housing having: couplings formed at each longitudinal end thereof, and one or more ports formed through a wall thereof and in fluid communication with an upper portion of a bore of the housing. The jetting tool further includes a valve mechanism isolating the housing bore upper portion from a lower portion thereof in a closed position and operable to an open position where the valve mechanism provides fluid communication between the housing bore portions.

Abstract: The present invention provides a valve and method for injecting a treatment fluid into a production zone of a hydrocarbon production well.

Abstract: A downhole hydraulic tool employing multiple nozzles in a selectable fashion from an oilfield surface. At least one of the nozzles of the tool is equipped with a burst disk such that fluid pressure directed from the surface may be utilized in activating the nozzle. The pressure may be driven to exceed a predetermined level for sake of the activating by way of sealing off access to other nozzle(s) therebelow, for example, by way of standard ball drop techniques. Thus, nozzle selectivity may be taken advantage of when a first nozzle wears out without requiring time consuming removal of the tool from the well for sake of remedial repairs or replacement.

Abstract: Wear is reduced in abrasive slurry service at an outlet into an annular space defined by the wellbore and around the tool. In a gravel packing application with a crossover, the slurry exits a central passage and goes into an internal annulus in the tool. Turning vanes that make at least one full turn and that have a height at least partially the height of the annular space are there to impart a swirl movement to at least a portion of the slurry stream. The swirling motion has beneficial effects of reducing turbulence which allows a velocity reduction for a comparable output volume.

Abstract: A reversible ported sub assembly has an upper connection assembly, a ported lower end assembly and a reversible ported jetting member. The reversible ported jetting member has a central through-bore and jet ports extending laterally from the central through-bore to the outer surface of the ported jetting member at an acute angle relative to the longitudinal axis of the central through-bore. The reversible ported jetting member can be flipped or reversed so that the jet ports can be optionally oriented generally upwardly or downwardly within a wellbore, as desired. A removable plug member can be optionally installed to prevent fluid flow through the ported lower end assembly.

Abstract: Systems and methods for maximizing energy recovery from a subterranean formation are herein disclosed. According to one embodiment, a selected subterranean open-hole interval is isolated and at least one fracture is stimulated in the isolated subterranean open-hole interval.

Abstract: A system for use with a subterranean well can include a fluid oscillator which discharges pulsating fluid from a tubular string in a direction at least partially toward an end of the tubular string proximate a surface of the earth. A method can include discharging a fluid from the tubular string, thereby applying a reaction force to the tubular string, which reaction force biases the tubular string at least partially into the well. Another method can include discharging a pulsating fluid from a fluid oscillator in a direction at least partially toward an end of the tubular string, and drilling into an earth formation with a drill bit connected at an opposite end of the tubular string in the well.

Abstract: The present invention relates to apparatus and methods for remotely adjusting the drill bit hydraulic horse power per square inch (HSI). Varying the nozzle geometry remotely without the need to pull the drill string outside the hole has obvious advantage. Changing the nozzle glow geometry results in changing the nozzle HSI which is beneficial to optimize drilling different rock formations in different drilling environment. There are many concepts to vary the nozzle size while drilling. The drill bit nozzle geometry can be varied by causing a change of at least one physical property of the environment. The variable geometry nozzle is not limited to drill bit, it can be placed within the inner flow passage or between the inner flow passage and annular flow passage for controlling flow profile within a wellbore, a tubular string or a flow conduit.

Abstract: Methods and washing tools are described for combined cleaning of an annulus in a well across a longitudinal section (L1) of the well, and subsequent plugging of the longitudinal section (L1).

Abstract: A flow control device for use in a wellbore which has a nozzle with an output to provide a jet of fluid and a structure proximate the nozzle. The structure is positioned a set distance away from the output of the nozzle, where the set distance is greater than a length of a potential core of the jet of fluid.